In England, one in four adults and more than one in 10 children are obese. Obesity increases the risk of cardiovascular disease, diabetes, hypertension, osteoarthritis, some cancers and mortality.
Most patients with obesity do not know what actions to take to reduce their weight, and lack motivation to make changes. Primary care teams have a crucial role in helping these patients take action.
Appetite control is complex. Fat, particularly abdominal fat, secretes adipokines - active messengers which impact areas of the brain, changing their sensitivity to hormonal satiety signals from the gut controlling appetite and energy expenditure and increasing inflammation. The greater the obesity, the more challenging weight loss, but it is never impossible.
1. Identifying high-risk patients
The QOF provides incentive to measure BMI, but does not reward intervention. GPs should ensure overweight and obese patients have the opportunity to weigh themselves. Keeping weighing scales openly in the consulting room, or a screened off area in the waiting room to allow self-weighing, facilitates discussion about weight.
If BMI is 25-35kg/m2, measuring waist circumference at the midpoint between the costal margin and the iliac crests provides additional information about health risk, and is a surrogate marker for high risk abdominal adiposity. NICE designates a waist circumference of ≥102cm in men and ≥88cm in women as very high risk, and a waist circumference of >94 and 80cm, respectively, as high risk.
Asian men and women have greater risk from central obesity and lower thresholds for action.
2. Behaviour change
GPs should raise the issue of weight whenever necessary, as weighing and brief interventions encourage some patients to make lifestyle changes.
As we know from personal experience, behaviour change is difficult. Precious time may be wasted offering specific guidance to those not yet convinced they need to make changes. Instead, assess readiness to change, asking: 'Do you want to lose weight?' or: 'Have you thought about losing weight?'
For patients who are not motivated to attempt weight loss, provide a leaflet outlining the benefits of modest, achievable weight loss. Document their BMI, and encourage them to return in three to six months, or before if they feel ready.
Surprising numbers are motivated to return.
3. Setting goals and monitoring progress
For those ready to change, we need to encourage them to set realistic goals, help them motivate themselves, instil confidence and elicit strategies for how they can achieve their goal.
A 5 to 10 per cent weight loss over three to six months is realistic. Weight maintenance may be appropriate for patients who are overweight with no co-morbidities, and when target weight is achieved. Regular weighing provides the motivation to overcome hurdles and build confidence.
A weekly weight loss of 0.5-1kg and a waist reduction of 1-2cm per month are good short-term targets. Monthly weight and waist monitoring by a healthcare support worker can be supplemented by self-measurement if possible.
4. Management options
Access to expert dietetic support and exercise on prescription are ideal interventions for patients ready to change. However, most GPs do not have access to such support and we therefore need concise ways to deliver lifestyle advice in one to two minutes at the end of a consultation.
A patient-centred approach allows the patient to choose achievable goals. Having several options, each supported by a patient leaflet, can prompt discussion; for example, a Mediterranean diet, self-referral to a weight loss group or other community support, identifying small changes and switching foods. Aim for a 500-600kcal deficit of energy over expenditure daily.
Dietary advice to help patients lose weight mirrors that given to patients with cardiovascular disease, hypertension or diabetes, increasing benefit for time spent. Patient.co.uk provides a range of leaflets on specific weight reducing advice.
Appetite control is complex, but encouraging slow eating allows gut-derived hormones to work on the satiety centres in the brain, decreasing caloric intake.
Encourage patients to move more, and reduce sedentary activities. Walking for 30 to 60 minutes five days per week is safe, or encourage use of a pedometer to measure daily step counts.
The daily average can be increased by 10 per cent each week, aiming for 10,000 steps (around four miles) daily.
Recommending increases in physical activity, accumulated in 10-minute bursts throughout the day, can be less threatening and more achievable than formal exercise programmes.
Exercise on prescription includes assessment, an individualised exercise programme and motivation package. Increasing activity, even if not accompanied by weight loss, improves adiposity and insulin sensitivity, and provides health benefits.
5. Obesity in children
Age and gender specific BMI charts are available for assessing children. Give advice if BMI ≥91st centile, and encourage family members, particularly whoever has responsibility for shopping and cooking, to participate in a healthy eating and activity programme too. Consider referral to the MEND programme or to paediatrics, particularly if BMI ≥98th centile.
6. Drug treatment
Orlistat is the remaining antiobesity drug licensed in the UK. It should be restricted to patients with a BMI ≥30kg/m2 or ≥28kg/m2 with risk factors.
Patients should be weighed regularly and treatment stopped at three months if at least 5 per cent weight loss is not achieved.
Many patients cannot tolerate optimal doses but for those that do, it encourages a low fat diet, which may be maintained after drug therapy stops. Metformin and the GLP-1 drugs can aid weight loss in patients with diabetes.
NICE recommends referral for bariatric surgery is restricted to those with a BMI ≥40kg/m2 or ≥35kg/m2 with comorbidities that could improve with weight loss, and only if all other lifestyle therapies have failed to provide clinically significant weight loss for more than six months.
Obesity can seem daunting, but encouraging simple lifestyle changes in those who are ready to change is hugely rewarding, and impacts on chronic diseases as well as quality of life. GPs are in the ideal position to help tame this epidemic.
- Dr Brown is a GP in Swansea and a member of the National Obesity Forum
- National Obesity Forum. Obesity care pathway and toolkit. 2005. www.nationalobesityforum.org.uk/images/stories/care-pathway-toolkit/Toolkit_supporting_obesity_care_pathway_annexes_1_to_9__Feb_07_2006.pdf
- NICE. Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children. CG43. London, NICE, 2006. www.nice.org.uk/nicemedia/pdf/CG43quickrefguide2.pdf